IFN-α and IFN-β belong to class I of the interferons, IFN-γ is the member of the class II of interferons. IL-28 and IL-29 are classified as class III interferons. These class III IFNs signal through a receptor complex consisting of IL10R2 (also called CRF2-4 or CD210b) and IFNLR1 (also called CRF2-12).